1. Field of the Invention
The present invention relates to a system for removing tissue from the human body.
2. Background Information
Tissue, including cataract lenses, are typically removed with an ultrasonically driven handpiece. For example, in a cataract procedure, it is commonly referred to as phacoemulsification. A phaco handpiece includes a tip that is inserted through an incision formed in the cornea. The tip is oscillated by a driver unit at an ultrasonic frequency. The oscillating tip breaks and emulsifies the lens.
The tip is coupled to an irrigation system that introduces irrigation fluid into the anterior chamber of the eye. The irrigation fluid cools the tip and maintains the ocular pressure of the anterior chamber. The irrigation fluid flows through an annular channel formed between the oscillating tip and an external protective sleeve. The sleeve is typically constructed from a material with a low coefficient of thermal conductivity to reduce the amount of heat that flows into the cornea. Excessive heating may permanently damage the eye.
The tip is also coupled to an aspiration system that pulls the emulsified tissue and irrigation fluid out of the anterior chamber. The emulsified tissue and irrigation fluid flow through an inner channel in the oscillating tip.
An intraocular lens is implanted into the eye after the cataract lens is emulsified and removed. It is desirable to reduce the size of the incision formed in the eye to reduce post-operative complications. There have been developed intraocular lenses that can be inserted through an incision approximately 2.5 millimeters (mm). Most phaco tips require an incision of 3 mm. It is difficult to further reduce the diameter of both the tip and the outer sleeve of a phaco tip to fit the 2.5 mm profile. It would be desirable to provide an ophthalmic cutting system that would require an incision smaller than incisions formed in prior art procedures. It would also be desirable to provide an ophthalmic cutting system that did not generate heat at the corneal incision. Other types of procedures would be enhanced by similar improvements.
One embodiment of the present invention is an ophthalmic cutter system that includes a cutter adapted to cut tissue such as a cataract lens and an irrigation handpiece adapted to hold the lens. The irrigation handpiece may be coupled to an irrigation system that introduces an irrigation fluid to the surgical site through the handpiece. The cutter may be coupled to an aspiration system that provides vacuum pulses to the surgical site. The vacuum pulses may pull tissue into a wire located at a distal end of a cutter cannula. The pulses may break and emulsify the tissue which is then aspirated through the cannula by the aspiration system. The wire may be connected to a controller that provides a current which is transformed into heat. The heat may assist in emulsifying the tissue.